Sempervivum plant named ‘Ruby’

ABSTRACT

A new and distinct variety of  Sempervivum  named ‘Ruby’ that is characterized by a fast-growing single rosette of thick succulent leaves arranged in whorls with reduced production of offsets and flowers and whose foliage color is conditioned by regional growing conditions and nursery practices. Foliage color ranges from bright red and green when plants have been overwintered in cold conditions to dark red and green when plants have not receiving any winter chilling.

Genus and species: Sempervivum hybrida.

Variety denomination: ‘Ruby’.

BACKGROUND OF THE NEW PLANT

The present invention relates to a new variety of Sempervivum commonlyknown as Stonecrop, or Hens and Chicks, or Houseleek. The presentinvention is known botanically as Sempervivum hybrida and will bereferred to hereinafter by the cultivar name ‘Ruby’.

Sempervivums are hardy perennial succulent plants which are grown andappreciated for the diversity of color and form in their foliage and fortheir tolerance of arid conditions. Many cultivars of Sempervivum are incommerce and involve a wide range of species and natural hybrids.Sempervivums are versatile in use and are grown in dry soils, rockgardens, and in containers. The genus Sempervivum is a member of thefamily Crassulaceae.

The inventor maintains in his nursery in Herrieden, Ansbach, Germany alarge collection of Sempervivums including named varieties and unnamedand unreleased seedlings raised by the inventor. The inventorestablished his Sempervivum breeding programme in 1996 with the primaryaim of developing a series of colorful varieties which form uniformlarge fast-growing rosettes with minimal production of offsets andflowers.

The inventor selected ‘Ruby’ in 2014 as a seedling which the inventorhad raised from seed resulting from the open pollination of Sempervivum‘Zundflamme’ (unpatented) as female female parent. The identity of themale parent is unknown. ‘Ruby’ was first asexually propagated in 2014 bythe inventor at the inventor's nursery by removal of lateral offsets(known also as chicks or pups) and rooting the offsets in well-drainedsoil. Since that time, under careful observation, the distinguishingcharacteristics of ‘Ruby’ have been determined stable and uniform andreproduced true to type in successive generations of asexualpropagation.

SUMMARY

The following traits have been repeatedly observed and represent thedistinguishing characteristics of the new Sempervivum variety named‘Ruby’. These traits in combination distinguish ‘Ruby’ from all otherexisting varieties of Sempervivum known to the inventor. ‘Ruby’ has notbeen tested under all possible conditions. Phenotypic differences may beobserved with variations in environmental, climatic, and culturalconditions.

-   -   1. Plants of ‘Ruby’ exhibit a fast-growing single rosette of        thick succulent leaves arranged in whorls.    -   2. The colors of the leaves of ‘Ruby’ are conditioned by        regional growing conditions and nursery practices.    -   3. When ‘Ruby’ is grown from plants which have over-wintered in        cold conditions, the older spring and early summer foliage is        bright red in color.    -   4. When ‘Ruby’ is grown from plants which have received winter        greenhouse protection or have been grown in mild winter        climates, the older spring and early summer foliage is dark red        in color.    -   5. The new foliage growth which emerges in the center of the        rosette is green in color.    -   6. Flowers of ‘Ruby’ are rarely observed and only on plants        which are at least two years old.    -   7. After one year of growth, plants of ‘Ruby’ are 7 cm in height        and 14 cm in diameter.    -   8. After two years of growth, plants of ‘Ruby’ are 12 cm in        height and 18 cm in diameter.    -   9. ‘Ruby’ is hardy to USDA Zone 4.

COMPARISON WITH PARENTAL LINES AND KNOWN VARIETY

The inventor selected ‘Ruby’ for its rapid production of very largerosettes compared to the many varieties in commerce. Whereas the femaleparent ‘Zundflamme’ also produces a rosette of red or red-purple coloredfoliage, plants of ‘Ruby’ grow more rapidly and achieve a greater sizeof plant in the same growing period. Typically, plants of ‘Ruby’ are atleast twice the size of same-aged plants of ‘Zundflamme’.

Varieties of Sempervivum which resemble ‘Ruby’ in their colorcombinations include Sempervivum ‘Orion’, Sempervivum ‘Mystic’ andSempervivum ‘Bedivere’ (all unpatented). However, none of thesevarieties possesses the vigor and growth rate of ‘Ruby’ which achievesat least twice the size as same-aged plants of these comparisonvarieties.

BRIEF DESCRIPTION OF THE PHOTOGRAPH

The accompanying photograph, FIG. 1, illustrates a two-year-old plant of‘Ruby’ which has been grown in a 2-gallon container out of doors inOxnard, Calif. The photograph was taken in mid-July. The plant in thephotograph has not received any winter chilling. The photographillustrates the newly emerging offsets of ‘Ruby’ which are observed ontwo-year-old plants.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed botanical description of the new Sempervivumvariety named ‘Ruby’. Observations, measurements, values and comparisonswere collected in Oxnard, Calif. in July 2020 from a two-year-old plantwhich has been grown out of doors in a 2-gallon container without anywinter chilling. Color determinations are made in accordance with The2007 Royal Horticultural Society Colour Chart from London, England,except where general color terms of ordinary dictionary significance areused. The growing requirements of the new variety ‘Ruby’ are similar tothe species.

-   Botanical classification:    -   -   Family.—Crassulaceae.        -   Genus and species.—Sempervivum hybrida.        -   Denomination.—‘Ruby’.        -   Common names.—Stonecrop, Hens and Chicks, Houseleek.-   Parentage:    -   -   Female parent.—Sempervivum ‘Zundflamme’.        -   Male parent.—Unknown.-   Plant:    -   -   Habit.—Basal rosette.        -   Use.—Garden and landscape planting, especially in dry            conditions, planted containers.        -   Suggested commercial container size.—4-inch container            (1-year-old plants), 2-gallon container (2-year-old plants).        -   Propagation method.—Removal and rooting of offsets.        -   Rooting system.—Fine and fibrous.        -   Root color.—NN155C.        -   Vigor.—Fast-growing through spring and early summer.        -   Crop time.—A 4-inch container will be filled out after four            months from planting a rooted offset. A two-gallon container            will be filled out after two years from planting a rooted            offset.        -   Plant dimensions (two-year-old plant, 2-gallon            container).—12 cm in height and 18 cm in diameter.        -   Cultural requirements.—Grow in free-draining soil and water            sparingly in morning or evening.        -   Pest and disease resistance.—None known to the inventor.        -   Pest and disease susceptibility.—None known to the inventor.        -   Hardiness.—USDA Zone 4.-   Stem: Stemless.-   Foliage:    -   -   Arrangement.—Leaves arranged in whorls.        -   Whorl quantity (range).—10-12.        -   Leaf quantity per whorl (range).—20-25.        -   Leaf attachment.—Sessile.        -   Leaf texture.—Succulent, fleshy.        -   Leaf division.—Simple.        -   Leaf margin.—Finely ciliate, hairs evenly spaced 0.25-0.5 mm            apart, length 0.25-0.5 mm, angled towards base, color            NN155D.        -   Leaf surface.—(Abaxial and adaxial): Glabrous, semi-glossy.        -   Leaf shape.—Obovate.        -   Leaf length (largest leaves).—6 cm.        -   Leaf width (largest leaves).—3 cm.        -   Leaf thickness (largest leaves).—4 mm.        -   Leaf color.—        -   Young leaves within tight rosette, unexposed to sunlight,            both surfaces.—141D, except apex color 45D.        -   Older leaves in lower whorls, both surfaces.—Predominantly            in range 47B-53B towards leaf apex with residual            yellow-green colors in range 151A to 151B towards leaf base            where hidden from direct sun.        -   Leaf apex.—Mucronate, spine 2-3 mm in length, soft.        -   Leaf base.—Truncate.        -   Venation.—Absent.-   Offsets:    -   -   Offset description.—Emerge as whole plant rosettes on short            stems within the older whorls. Stems lengthen with age.            Offsets may be removed with stems attached for propagation.        -   Offset quantity.—10-15.        -   Offset stem dimensions (if not removed).—Up to 10 cm in            length, 4 mm in diameter.        -   Offset dimensions.—1.5-2.0 cm in height and diameter.        -   Offset foliage description.—Whorled, leaves initially            colored 141D (both surfaces), becoming orange-red 34A on            surfaces exposed to sunlight.-   Inflorescence: Inflorescences rarely observed and typical of the    genus.    -   -   Inflorescence type.—Terminal cyme.        -   Inflorescence dimensions.—6 cm. in height, 5 cm in diameter.        -   Blooming season.—Late summer or fall.        -   Inflorescence quantity (if present).—1 or 2.        -   Inflorescence stems (peduncles).—Initially upright, emerging            from within the rosette of whorls, not from the base. Stems            arch as inflorescence ages and dies.        -   Stem texture.—Fleshy, surface downy.        -   Stem dimensions.—20-30 cm. in length, 3-5 mm in diameter.        -   Stem color.—144D-145A.        -   Flower quantity.—Approximately 50 per cyme.        -   Flower shape.—Stellar, radially symmetrical.        -   Flower dimensions.—5 mm in height, 6 mm in diameter.        -   Fragrance.—None observed.        -   Lastingness of individual flower (on the plant).—10-14 days.        -   Persistent or self-cleaning.—Persistent.-   Bud:    -   -   Bud shape.—Spherical.        -   Bud dimensions (immediately prior to opening).—3-4 mm in            diameter.        -   Bud surface.—Pubescent.        -   Bud apex.—Rounded.        -   Bud color.—26B.-   Petals:    -   -   Petal quantity.—16.        -   Petal color (both surfaces).—36D, becoming NN155C when            flower is fully expanded.        -   Petal shape.—Lanceolate.        -   Petal apex.—Acute.        -   Petal base.—Truncate.        -   Petal margin.—Smooth, entire.        -   Petal dimensions.—5 mm, 1 mm in width.        -   Petal surface texture.—Matte, paper-like.-   Sepals:    -   -   Sepal quantity.—16.        -   Sepal shape.—Lanceolate.        -   Sepal color.—Ranges between 34A and 34C except 46A towards            apex.        -   Sepal apex.—Acute.        -   Sepal base.—Truncate.        -   Sepal margin.—Smooth, entire.        -   Sepal dimensions.—3-4 mm in length, 1 mm in width.        -   Sepal surface texture.—Matte, abaxial surface pubescent.-   Pedicel:    -   -   Pedicel shape.—Cylindrical.        -   Pedicel color.—34C.        -   Pedicel surface texture.—Glabrous.        -   Pedicel dimensions.—8 mm in length and 2 mm in width.-   Reproductive organs:    -   -   Stamens.—24-32 in number, arranged in one or two concentric            rings around central pistil cluster.        -   Filaments.—3-4 mm in length, color 46B.        -   Anthers.—Develop within orange-red membrane, color 45C.        -   Pollen.—Appears as membrane is shed, color 9A and bright,            quantity moderate.        -   Pistils.—Approximately 12 in number.        -   Style.—Approximately 3 mm in length, color 17C.        -   Stigma.—Conical, color 34C.        -   Ovary.—Not observed.-   Seed: Extremely fine, dust-like, color dark grey.

I claim:
 1. A new and distinct cultivar of Sempervivum plant named‘Ruby’ as described and illustrated herein.